add driver to Scene.current_frame?
You cannot add a driver to the frame_current property of the scene object, error message from console.

&gt;&gt;&gt; C.scene.driver_add('frame_current')
Traceback (most recent call last):
  File "&lt;blender_console&gt;", line 1, in &lt;module&gt;
TypeError: bpy_struct.driver_add(): property "frame_current" not animatable


You could do something with frame change handlers.

import bpy

def lockscenes(scene):
    if scene.name == "Scene": # master scene
        f = scene.frame_current
        for scene in bpy.data.scenes:
            if scene.name == "Scene":
                continue
            scene.frame_set(f)
    return None

bpy.app.handlers.frame_change_post.append(lockscenes)